Is this grammatical? "You are who I love."

I've just got wondering if this sentence is grammatically correct:

You are who I love.

This is what I am thinking:

Let's focus on the who clause, then you can find that the missing element from this clause is actually an object after the verb love. Therefore, who should be changed to whom, which is an object relative pronoun.

• You are whom I love.

Now, the whom clause has no problem, but you can see that whom clause works as an object. However, there is the place at which a subject complement should be. So, I should either change the whom clause back to a who clause or make you into an object.

1. You is whom I love.
2. It's you whom I love.
3. Whom I love is you.

After all that, I came this far with these three sentences and I think the most appropriate sentence is the second one, but I'm not sure if my assumption is right; the way I fixed the sentence, is it right?

The original is probably eliding a word.

I think this works:

You are she whom I love.

'are' is a linking verb here; 'whom' is introducing an appositive phrase and is the object of 'love'. What's missing in the original is the predicate pronoun ('she', 'he', etc.).